Halobacterium has a photosynthetic membrane that is coloured purple. Its photosynthetic action spectrum is exactly complementary (opposite to)the action spectrum for green plants. What wavelengths of light do the Halobacterium photosynthetic pigments absorb?
A)red and yellow
B)blue, green, and red
C)green and yellow
D)red and green
E)blue and red

Question

Quizplus · Accepted Answer

Since the photosynthetic action spectrum of Halobacterium is complementary to that of green plants, it suggests that Halobacterium absorbs the wavelengths of light that green plants do not absorb effectively. Green plants absorb mainly blue and red light, but not much in the green range. Therefore, the best choice is E, which includes blue and red light.

Halobacterium Has a Photosynthetic Membrane That Is Coloured Purple